Color correction of negatives and printing plates



Oct. 24, 1939. w, l- W|LK|NS0N 2,177,195

COLOR CORRECTION OF NEGATIvEs AND PRINTINGJLATES Filed Feb. 8. 1939Patented Oct, l24, 1939 COLOR CORRECTION F NEGATIVES AND PRINTING PLATESWilliam J. Wilkinson, Eastcheste'r, N. Y., assignor oi' one-half toMiehle Printing Press and -Manufacturing Company, Chicago, Ill.; acorporation of Illinois v Application February 8, 1939, Serial No.255,221

7 Claims.

(Cl. S51-5.1)

The current invention, presented diagrammatied or corrected by.employing asa rectifying cally in the single view of the associateddrawing forming'a part of this speciiication, relates to themodification or correction of photographic, color-separation negativesand of the corresponding printing-plates of an original multicoloredsubject, whereby the ilnal print made t from the printing-platesproduced from such negatives will accurately represent the originalAsubject in all its colors, the present invention constituting animprovement over that presented in my United States Patent 2,099,916,Color-correctned printing, granted November 23, 1937.

According to the invention of such patent, the

u color-separation negatives, made through the usual lters, wereimproved by the employment of certain overlay transparencies associatedtherewith, the overlay for the yellow-separation negative comprising aphotographic-transparency made through a combination of (a) apositive-transparency made from'the yellow-separation negative and (b)the blue-separation negative; the overlay for the red-separationnegative consisting of a photographic'positive-transparu ency producedfrom the blue-separation negative;

and the overlay for the blue-separation negative comprising atransparency made through a com- 4 v bination of (a) apositive-transparency made from the blue-separation negative and (b) then yellow-separation negative. l,

-, In practicing such-patented procedure, in some instances, trouble wasencountered with the violets, and the present invention involves a.substantial improvementV over such earlier method u in that it effectsthe elimination of the undesired graphic positive-transparency vfrom thel yellow-I separation negative and' thenm'akingf the photographicoverleving* ransparency through such positive-transparenc and thered-separation 4,5v negativev while the two are superposed and inregister with one another. l

The reds-separation negative, as in the previous instance, is correctedby a transparency-overlay made through-the superposed registered bluef j5o separation negative and a positive from the redseparationnegativepand, ordinarily, the blueseparation negativen-Quiros noalternative overlay.

In case a black negative' is-used, which, oi'

Il course. is not always necessamitmaybe modioverlay thereforaphotographic-positive transparency made through the yellow-separationnegative,l or, a normal black exposure of the subject may be made toproduce a negative Without 5 the use of a iilter, and from this, whenpracticing the hemi-tone gravure method, as set forth in such Patent2,099,916, from such negative a normal heini-tone positive-transparencyis made depicting the blacks by dots in checkerboarddesign, but whenetching the printing-plate its period of action is only about one-iifththe etching time for the other printing-plates.

Those negatives requiring correction or improvement having been suppliedwith the proper overlays as described above, photographic-positivetransparencies are made for all of the negatives, and, from thesecolor-separation positives, in the manner disclosed in such patent,etched, heini-tone, color, gravure printing-plates are made, theprinting therefrom being done either in three or four colors, as thecircumstances dictate.

The ioregoing, coupled with the disclosure in said United States Patent2,099,916 is sufllcient for the practice of the new procedure, but itIis to be understood that the latter is not necessarily restricted andconned to the exact details set forth, the scope of the invention beingdefined in the appended claims which should be construed as genericallyas the condition of the prior art permits with maintenance of theirvalidity.

The foregoing procedure, is not limited to the production of screened.heini-tone positive-transparencies and their correlativeprinting-plates, the novel color correction method being suitable lforuse in other relations.

1. The process of making:

(a) Yellow, red and blue color-separation pho- 40 to,graphic-negativesofa multi-color subject,

(d) Correction of said yellow-separation negative by applying saidoverlay thereto and in register therewith, 1 i

(e) A second positive photographic-transparency through saidred-separation negative,

(l) A corrective photographic overlay-transvan parency for saidred-separation negative through said second positive-transparency andsaid blueseparation negative While the two are in superposed registeredrelation,

(g) Correction of said red-separation negative by'applying its' saidcorrective overlay thereto and in register therewith, and

(h) Corresponding printing-plates from said corrected yellow-separationVand red-separation negatives and said blue-separation negative.

2. The process of making:

(a) Yellow, photographic-negatives of a multi-color subject,

(b) A positive photographic-transparency through `said yellow-separationnegative, y

(c) Acorrective photographic, overlay-transparency for saidyellow-separation negative comprising making a photographic-transparencythrough said positive-transparency.and said redseparation negative whilethe two' are in superposed registered relation,

(d') Correction of said yellow-separation negative by applying saidoverlay thereto and in register therewith,

(e) A second positive photographic-transparency through saidred-separation negative,

(f) A corrective photographic overlay-transparency for saidred-separation negative through said second positive-transparency andsaid blue-separation negative while the two are in superposed registeredrelation,

(y) Correction of said red-separation negative by applying its saidcorrective overlay there- Y to and Ain register therewith,

(h) A photographic positive-transparency through each of said correctedyellow-separation and red-separation `negatives and said blueseparationnegative, and

(i) An etched hemi-tone gravure printingplate from each of saidlast-mentioned positivetransparencies.

3. The process of making:

(a) Yellow-separation, red-separation, blueseparation. and blackphotographic-negatives of a multi-color subject,

(biA positive photographic-transparency through said yellow-separationnegative, l

(c) A corrective photographic overlay-transparency for saidyellow-separation negative comprising making a photographic-transparencythrough said positive-transparency and said redseparation negative whilethe two are in superposed registered relation,

(d) Correction of said yellow-separation negative by applying Ysaidoverlay thereto and in register therewith, i

(e) A second positive photographic-transparency through saidred-separation negative,

(f) A corrective photographic overlay-transparency for saidred-separation negative through said second positive-transparency andsaid 'blueseparation negative while .the two are in superposedregistered relation,

red and blue color-separation'` (e) A second positivephotographic-transparency through said red-separation negative,

A corrective photographic overlay-transparency for said red-separationnegative through said second positive-transparency and saidblueseparation negative while the two arev in superposed registeredrelation,

(y) Correction of said red-separation negative by applying its saidcorrective overlay thereto and in register therewith,

(h) A photographic positive-transparency through each of said correctedyellow-separation and red-separation negatives and said blueseparationand`black negatives, and

(i)`\ An etched hemi-tone 'gravure printingplate from each of saidlast-mentioned positivetransparencies.

5. The process of making:

(a) Yellow-separation, red-separation, blueseparation and blackphotographic-negatives of a multi-color subject,

(b) A positive photographic-transparency through said yellow-separationnegative,

(c) A corrective photographic overlay-transparency for saidyellow-separation negative comprising making a photographic-transparencythrough said positive-transparency and said redseparation negative whilethe two are in superto and in register therewith, and

(7L) Correction of said black negative by applying said positive fromthe yellow-separation negative thereto and in register therewith, and(i) Corresponding printing-plates from said corrected yellow-separation,red-separation, and

black negatives and said blue-separation negative.

6. The process of making:

(a) Yellow-separation, red-separation, blueseparation and blackphotographic-negatives of a multi-color subject,

(b) A positive photographic transparency through said yellow-separationnegative,

(c) A corrective photographic overlay-transparency for saidyellow-separation negative comprising making aphotographic-transparencyv -through said positive-transparency and saidredseparation negative while the two are in superposed registeredrelation,

(d) Correction of said yellow-separation nega.-

tive by applying said overlay thereto and in register therewith,

negative tive by applying its said corrective-overlay there- (e) Asecond positive photographic-transparency through said red-separationnegative,

(f) A corrective photographic overlay-transparency for saidred-separationnegative through said second positive-transparency andsaid blueseparation negative while the two are in superposed registeredrelation,

(y) Correction of said red-separation negative by applying itssaidcorrective overlay thereto and in register therewith,

(h) Correction of said black-negative by applying saidpositive-transparency made from saidA yellow-separation negative theretoand in register therewith,

(i) A positive-transparency through each of said correctedyellow-separation, red-separation and black negatives and saidblue-separation negative, and

(i) An etched hemi-tone gravure printingplate from each of saidlast-mentioned positivetransparencies.

'7. The process of making:

(a) Yellow-separation, red-separation, blueseparation and blackphotographic-negatives of a I multi-color subject,

.(b) A positivev photographic-transparency parency for saidyellow-separation negative comprising making a photographic-transparencythrough said positive-transparency and said redseparation negative whilethe two are in superposed registered relation,

(d) Correction of said yellow-separation negative by applying saidoverlay thereto and in register therewith,

(e) A v second positive photographic-transparency through saidredseparation negative,

(f) A corrective photographic overlay-transparency for saidred-separation negative through said second positive-transparency andsaid blueseparation negative while the two are in superposed registeredrelation,v

(g) Correction of said red-separation negative by applying its saidcorrective overlay thereto and in register therewith,

(h) A positive-transparency through each of said correctedyellow-separation and red-separation negatives and said blue-separationand black negatives, and

(i) etched hemi-tone gravure printingplate from each of saidlast-mentioned positivetransparencies, the depth of etching of saidblack printing-plate being a small fraction of that of the otherprinting-plates.

WIILIAM J. wILKmsoN.

